Have you blocked some of your friends on Facebook intentionally or unintentionally? Don't worry, you can unblock them whenever you choose. Blocking friends simply means that those friends have been forbidden from seeing your timeline, sending you messages, etc. Most people actually disturb their friends a lot, hence the reason for the action: Blocking. So, let's say that you've had a change of heart and you want to unblock them, here's how to go about it:

On Your Facebook Application

Tap on the menu button on the top of your Facebook page

Scroll down to Account Settings

Tap on "Blocking" to show you a list of your blocked friends

On the extended right of the name of the person you want to unblock and tap on "Unblock"

On the screen that pops up, you will be asked if you are sure you want to unblock the person, tap on "Unblock"